桂林喀斯特地貌分布区苏云金芽孢杆菌菌株的分离鉴定  

Isolation and Identification of Bacillus thuringiensis Strains from Guilin Karst Landform Area

作　　者：孙晓东[1,2] 张静涛[2] 束长龙[2] 郝再彬[3] 高继国[1] 张杰[2] 宋福平[2] 

机构地区：[1]东北农业大学生命科学院,哈尔滨150030 [2]中国农业科学院植物保护研究所/植物病虫害生物学国家重点实验室,北京100193 [3]桂林工学院,桂林541004

出　　处：《中国生物防治》2009年第2期138-142,共5页Chinese Journal of Biological Control

基　　金：国家“十一五”863计划(2006AA022189,2006AA10A212)

摘　　要：从桂林喀斯特地貌分布区采集了165份天然土壤样品,从中分离出10株苏云金芽孢杆菌。光学显微镜观察发现有菱形、球形、不规则等晶体类型。通过核酸电泳比对其大质粒DNA的图谱来区分菌株的类型,发现该批菌株有良好的多样性。对这10株菌进行cry1、cry11、cry2、cry3、cry4、cry5、cry6、cry7、cry8、cry9、cry10类基因的PCR-RFLP鉴定,在8株菌中分别发现含有cry1、cry11、cry2、cry3等基因类型,而G4、G6菌株中不含有已知基因。SDS-PAGE分析了10株野生菌株的杀虫晶体蛋白表达谱,发现有10株表达约130kD蛋白,有3株既表达130kD蛋白又表达60kD蛋白。对大猿叶甲、小菜蛾进行了杀虫活性测定,发现了一株对大猿叶甲具有较高毒力的菌株G8,其LC_(50)为48.2μg/ml,置信区间为9.6～1.4ml;有6株菌株对小菜蛾有高活性。One hundred and sixty five soil samples were collected from Guilin Karst landform area, and 10 strains of Bacillus thuringiensis were isolated from the samples. Light microscope observation indicated that these Bt strains contained crystals in shape of bipyramidal, spherical, square, irregular and so on. Plasmid DNA pattern of the strains formed by agarose gels electrophoresis was compared and it showed a great diversity for these strains. Cry1, cry11, cry2 and cry8 type genes were found in these strains by PCR-RFLP method, but the cry gene-types of two strains G4 and G6 were not known. SDS-PAGE results showed that 10 wild strains could express Cry proteins with 130 kD molecular mass, and 3 isolates could express both 130 kD and 60 kD protein. Bioassay results of the 10 strains indicated that six of them were toxic to Plutella xylostella larvae, and G8 was of highly insecticidal activity to Colaphellus bowringi larvae with 50% lethal concentration （LC50） at 48.2 μg/ml.

关 键 词：苏云金芽孢杆菌 CRY基因 PCR-RFLP 杀虫活性 

分 类 号：S476.11[农业科学—农业昆虫与害虫防治]